Engineering Commons^™

Vibrations Due To Pile Driving, M. R. Lewis, J. R. Davie

International Conference on Case Histories in Geotechnical Engineering

Vibrations due to pile installation have long been a concern to owners, contractors, and engineers. Specifically, what levels of vibrations can be assumed for a given pile, hammer, and subsurface conditions and how can these levels be predicted in advance of construction so an assessment of nearby structures can be made? This paper presents the results of vibration monitoring at several sites where various piles and pile hammers have been used, and recommends a conservative method of predicting peak particle velocity at the ground surface near pile installations. Where sensitive structures are involved, a response spectrum analysis is recommended.

Dynamic Response Of Block Foundations, Vijay K. Puri, Braja M. Das

International Conference on Case Histories in Geotechnical Engineering

This paper presents the results of comparison of the computed and observed response of two block foundations made of concrete. The test blocks measuring 3.0m x 1.5m x 0.7m and 1.5m x 0.75m x

0.70m were cast on level ground. The blocks were excited into vertical vibrations using a speed controlled mechanical oscillator. The amplitudes of vibration at different frequencies of excitation were measured in each case using acceleration transducers mounted on appropriate faces of the block. Dynamic shear modulus at this site was also determined b¥ conducting in-situ tests namely the wave propagation test, the cyclic plate load test, …

Dynamic Compaction Test On An Hydraulic Silty Sand Fill, G. Varosio, P. Grimaldi, G. Canepa

International Conference on Case Histories in Geotechnical Engineering

Dynamic compaction resulted to be the most effective method to compact a very loose hydraulic silty sand fill, with a fine content from 25 to 90 per cent. Two levels of compaction energy were tested. The soil settlements enforced by these energies were verified with reference to the concept of saturation energy and by means of a simplified analysis of the physical model.

General Report Session No. 4: Case Histories Man-Made Vibrations, Vijay K. Puri, James P. Lee

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

An Unsuccessful Urban Deep Excavation In Soft Soils, Richard Rodgers, Michael Majchrzak

International Conference on Case Histories in Geotechnical Engineering

This case history presents, from a geotechnical engineer's viewpoint, various technical, budgetary, coordination, staffing and "hidden agenda" issues that contributed to poor performance of a shored deep excavation 10 soft soils. The anticipated and actual construction procedures are discussed and compared. In addition, approaches to stabilize significant movements of the shoring, and the methodology needed to justify a satisfactory future performance of a pile foundation system that was speculated to be damaged are discussed. By highlighting these issues, it is hoped geotechnical engineers will anticipate and better deal with the issues under their influence, understand issues over which they may …

General Report On Session No. 5: Case Histories Of Retaining Structures And Deep Excavations, John T. Christian, Çetin Soydemir, Alan J. Lutenegger

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

A Case History Of The Collapse Accident Of A Temporary Earth Support Structure, Noriyuki Horii, Shigeo Hanayasu, Yasuo Toyosawa, Satoshi Tamate, Takakazu Maruyasu

International Conference on Case Histories in Geotechnical Engineering

This paper presents a case study on the collapse accident of a temporary earth support structure. The examination of the design plans and investigations of the construction site where the accident occurred bas been carried out to throw light on the accident situations. Some causes of the accident occurrence which have been derived from these examinations and countermeasures for prevention of these types of accidents are discussed.

Cut And Cover At Landrückentunnel North, R. Pöttler

International Conference on Case Histories in Geotechnical Engineering

The paper deals with a tunnel structure which has been designed in a very economic way, taking account of best estimate ground parameters and high sophisticated numerical models for simulating the reinforced concrete behaviour. Some changes were made during construction of the tunnel, to speed up the construction procedure. During the backfill of the tunnel higher displacements than calculated occurred.

Discussions And Replies Session 5, Shamsher Prakash, J. N. Gómez, Eyjolfur Arni Rafnsson, Roy E. Olson

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Earth Pressures On Walls Of A Deep Excavation, Z. C. Moh, R. N. Hwang

International Conference on Case Histories in Geotechnical Engineering

This paper reports recorded earthpressures acting on diaphragm walls during a deep excavation carried out in a soft ground and discusses factors affecting the readings. The main theme of the paper is on wall friction and its influence on vertical earthpressures. It can be demonstrated that the assumption normally adopted in the design of the retaining structures for braced excavations that the vertical earthpressures equal to the overburden pressures could be erroneous. As a result, the vertical pressures on the active side are often over- estimated and those on the passive side under-estimated. In conclusion, it is appropriate for soft …

Failure Of A Large Circular Excavation, R. E. Olson, R. E. Heuer

International Conference on Case Histories in Geotechnical Engineering

A circular excavation, 117 feet (36 m) in diameter by 90 feet (27 m) deep, was designed by an experienced engineering firm and construction was performed by an experienced contractor. Nevertheless, the excavation support system suffered a complete collapse long before the maximum depth was reached. The failure is described and its causes are discussed.

Failure Of A Twenty-Foot High Retaining Wall, R. E. Olson

International Conference on Case Histories in Geotechnical Engineering

A cantilever retaining wall, designed in apparent accord with provisions in a civil engineering handbook, failed soon after construction. Analyses of the causes of the failure are presented.

Failure Of Sewerage Mains Constructed In Soft Estuarine Deposit, M. M. Rahimi, C. Karwaj, P. K. Deb

International Conference on Case Histories in Geotechnical Engineering

Rising and effluent mains of 600 mm and 750 mm diameter were constructed at two adjacent creek crossings in New South Wales, Australia. A bund wall was constructed across each creek and the mains were laid in a trench excavated through the bund wall into the underlying soft deposit. Foundation preparation consisted of pouring rockfill into the trench and compacting with a few strikes of the excavator bucket. After construction unacceptably large joint openings of up to 120 mm in width were measured. The authors were engaged to undertake a review of the geotechnical characteristics of the crossings and comment …

Geotechnical Performance Of A Tunnel In Soft Ground, A. B. Parreira, R. F. Azevedo

International Conference on Case Histories in Geotechnical Engineering

The analysis of a tunnel section excavated through soft ground is presented. The tunnel construction was monitored and its behavior is compared with results obtained by a numerical simulation. The field instrumentation and the geotechnical properties of the site are presented and the modeling of the soil behavior using Lade's model discussed.

Large Excavation Behavior At Petacalco, Mexico, G. Castellanos, S. Sedano

International Conference on Case Histories in Geotechnical Engineering

The pumping sump for the Petacalco, Gro. Power Plant required for its construction an excavation 100 x 87 m plan and 11 m depth. The calculated flow towards the excavation was 370 l/s. Two perimetral systems were proposed to control the inflow water: Cut-off wall or conventional pumping system. After a technical-economical analysis, the first one was selected. Due to construction delays of the cut-off wall and program construction demands, the excavation began simultaneously and advanced faster than the wall. The observed inflow water was ten times lesser than the predicted one, so that the construction of the wall was …

Measurements And Predictions On The Elkhart Greek Culvert, P. M. Byrne, T. Srithar, C. B. Kern

International Conference on Case Histories in Geotechnical Engineering

This paper describes field measurements and analysis carried out on the Elkhart Creek soil arch culvert structure in British Columbia, Canada. The structure has a span of 13.4 m, a rise of 7.3 m, and a soil cover of 9.6 m. The original structure collapsed during backfilling in October 1987. A new structure of the same design was built in the Fall of 1989, and because of controversy regarding the design thrust value, it was instrumented to measure thrust, moment, and displacements in the arch. Displacements and stresses in the soil were also measured. The measured thrust values were much …

Performance Of A Braced Excavation In Siltstone, Wolfgang Roth, Anthony Stirbys, Corbin De Rubertis, Richard Ellis

International Conference on Case Histories in Geotechnical Engineering

A case history and analysis are presented of a 76-foot deep braced excavation in competent silt- and claystone formations. Soldier piles and lagging were supported by three levels of struts above three levels of tie-backs. During construction, measured strut loads exceeded design levels by up to 100 percent, and additional struts were installed in the upper portion of the excavation. Back analysis performed after construction indicated that large horizontal insitu stresses (K_o= 1) in the region had contributed to the overloading. It was also shown that the problem had been compounded by the practice of pre loading the …

Prediction Of Structural Slurry Wall Behavior, Mark Tamaro, Pablo Lopez, Sibel Pamukcu

International Conference on Case Histories in Geotechnical Engineering

The following study was undertaken with the intent of improving the ability to accurately predict the behavior of structural slurry walls. An existing wall, employed during the construction of the Washington D.C. subway system, was examined using four different analysis methods. The actual stresses and displacements of this wall were measured, providing a basis for investigating the accuracy of the different analysis techniques. The results obtained warrant the use of one particular approach, referred to in this study as the "Beam on Elastic Foundation Method". This method provided the most useful simulation of the soil/structure interaction that occurred during construction …

Reinforced Earth® Wall Supported By An Unstable Foundation, T. Schick, S. R. Neely, A. A. Joseph

International Conference on Case Histories in Geotechnical Engineering

This paper updates a paper presented in 1987 at a meeting of the Texas section of the American Society of Civil Engineers. The 15-foot high, Reinforced Earth® Wall was constructed in 1981 to remediate slope instability at a site underlain by clay/concrete rubble fill to a depth of approximately 24 feet below the top of the wall. Additional data are presented on vertical and horizontal movements measured along the middle portion of the 350-foot long wall which has exhibited the most movements.

Performance Of Earth Retention System, St. Louis Data Center, Thomas L. Cooling, Marty C. Hagerty

International Conference on Case Histories in Geotechnical Engineering

The design and performance of the earth retention system for a 35 ft deep excavation in medium clay is described. The earth retention system consisted of soldier piles and lagging with tieback anchors. One level of tiebacks included helical anchors installed in loose to medium dense sand. Behavior of the helical anchors in contrast to conventional drilled-in anchors is discussed.

Measured Behavior Of A Deep Excavation In Weathered Rock, M. T. Mcrae, S. S. Kishnani, J. C. Burton

International Conference on Case Histories in Geotechnical Engineering

An instrumented deep excavation in weathered rock adjacent to a deflection-sensitive historical building is described. Two permanent shoring systems were used, presenting an opportunity to measure and compare their behaviors. Adjacent to the historic structure, a tied-back drilled pier wall was used, while the remainder of the excavation was supported by a tied-back shotcrete wall constructed in top-down fashion. Instrumentation included inclinometers, tiltmeters, and tieback load cells, supplemented by optical surveys. Both support systems performed well, with movements within acceptable ranges. The maximum horizontal deflection of the drilled piers was 0.33 inch (8 mm), one-third to one-fifth that of the …

A New Monitoring Method And Its Application, Yuanyou Xia, Hongwen Zhou

International Conference on Case Histories in Geotechnical Engineering

For the monitoring of one hydroelectric station slope's large caves in their excavation period, the paper puts forward a new monitoring method suited to monitor large, dangerous caves. In this paper, the characteristics of the new method and eight successful forecasts on the roof falls and surrounding rock collapses of the caves in the their digging period by using the new method are presented in detail.

Diversion Tunnel Of A Hydroelectric Plant On Nestos River (Greece). A Case Study, T. Makedon, G. Dimopoulos, C. Marangos

International Conference on Case Histories in Geotechnical Engineering

A complete description of a geological and geotechnical investigation for the construction of a diversion tunnel in Platanovrisi dam area, East Macedonia, Greece is given. The numerical stress analysis and stress failure analysis results are presented, along with results of structurally controlled failure modes. The requirements for the application of the method are described. The conclusions from the application of the failure criterion, as well as the comparison between the analysis and the actual construction results have been discussed.

Geotechnical Problems Of The Underground Excavation In The Deccan Basalts Sarovar (Narmada) Project, Gujarat, India, Indra Prakash, J. S. Sanganeria

International Conference on Case Histories in Geotechnical Engineering

The Sardar Sarovar (Narmada) Project, Gujarat State envisages the construction of an underground power house (6x200 MW) and its ancillary structures in the Deccan basalt. The basalt lava flows in the area are intruded by dolerite dykes and sills and dissected by fractures, shears and faults. These features have posed varied geotechnical problems like block falls, wedge failures, roof collapses and water seepage during the excavation of machine hall, access tunnel, draft tube tunnels and exit tunnels. The adequacy of support system designed on the basis of Barton’s and Bieniawski’s rock mass classification is constantly monitored and reviewed from time …

Performance Of A Large Diameter Tunnel In Weak Rocks, J. C. Chern, Y. L. Chang, C. C. Lin

International Conference on Case Histories in Geotechnical Engineering

The correlation of tunnel movement versus rock mass quality was investigated using actual monitored data as well as theoretical studies. Results revealed that meaningful empirical correlation between the commonly used rock mass rating system and tunnel deformation can be obtained only if geological structure and in-situ stresses are taken into account. In this respect, the commonly used rock mass rating system is not very suitable for such purpose. A new parameter using rock mass strength normalized by in-situ stress level appears to be more suitable for establishing the relationship between tunnel deformation and rock mass quality.

Prediction-Forecast And Slip-Control For One Slope, Ruigeng Zhu, Yuanyou Xia, Wenxing Lu

International Conference on Case Histories in Geotechnical Engineering

Firstly, combining the engineering geological conditions of the slope, this paper analyses the forms and main causes of the slope possible slip, and predicts the slope's stability in the different construction periods of the gully at the bottom of slope. In the basis of these, the work plan of quick cutting quick erecting for the gully is emphatically discussed. Then, the paper presents the slope monitoring method and monitoring results. At last, the paper re-analyses the site-monitoring data. The results of monitoring and re-analysis prove that work plan of quick cutting and quick erecting is correct and the poured concrete …

Surface Subsidence Over Deep Solution Mined Storage Cavern Field, Minh D. Nguyen, S. Braham, J. G. Durup

International Conference on Case Histories in Geotechnical Engineering

Ten years observation by GDF on Tersanne solution-mined gas storage field, offers the opportunity for a mechanical interpretation of the surface subsidence. According to the geological context, the rockmass was modellised by a two-layered medium with highly contrasted mechanical behavior: a soft elastic clay cover, and a viscous salt mass. Given the field uncertainties, mostly related to the cover layer, and the three- dimensional nature of the problem, indirect methods were used to obtain bounds for the surface subsidence evolution and a parametric study was performed. Comparison with data of the field allows to determine likely rock mass parameters, put …

Deformation Prediction For An Underground Opening, Yang Zhifa, Du Yonglian, Wang Sijing, Ji Liang Jie

International Conference on Case Histories in Geotechnical Engineering

For excavation of a large underground opening, how to predict the deformation caused by excavation is a subject of interest to the engineers. In this paper, the main underground opening of Lubuge Hydroelectric Power Station will be cited to explain the method predicting its deformation. The successful application shows that the method called MDBD could, perhaps, be used for deformation prediction of other large underground excavations if they satisfy some special conditions basically.

Geotechnical Problems Encountered During The Excavation Of Underground Cavities For Varahi Hydro Electric Project, H. V. Eswaraiah, V. S. Upadhyaya, B. N. Vishwanath

International Conference on Case Histories in Geotechnical Engineering

Varahi river in Karnataka State, India originates on the Western Ghats and is harnessed for power generation by constructing three dams. The water is conveyed through two inclined pressure shaft to the underground power house below the Ghats. The underground power house of the Varahi Hydro Electric Project executed by the Karnataka Power Corporation has 2 units of 135 MW each in the first stage with a provision to add two more identical units. Three underground cavities are excavated parallel to one another for housing the rotary valves, generators and the transformers respectively and are at a gee-static head of …

Grauholz Railway Tunnel, Switzerland: Geotechnical Prediction And Its Influence On The Chosen Method Of Excavation, W. Harsch

International Conference on Case Histories in Geotechnical Engineering

Difficult ground was predicted for the 6.3 km long Grauholz Tunnel. The geology comprises complex soft-ground above and below the groundwater and rock conditions. The examples described led to the choice of a mixshield machine to excavate the 11.6 m diameter tunnel. This machine can operate in either closed (slurry) or open (TBM) mode. Experiences with this installation are discussed.